GB2056354A

GB2056354A - Safety razor heads

Info

Publication number: GB2056354A
Application number: GB8016955A
Authority: GB
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1979-05-25
Filing date: 1980-05-22
Publication date: 1981-03-18
Also published as: BR8003234A; US4335508A; CA1140321A; GB2056354B; US4443940A; DE3019399A1; FR2457155A1

Description

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GB 2 056 354 A 1

SPECIFICATION 65

Safety razor heads

This invention relates to safety razors in which provision is made for relative movement between 5 different skin engaging elements of the razor head 70 to take place during shaving in dependence upon the reaction forces encountered by the elements.

The term "skin-engaging elements" refers to the blade or blades of the razor, the guard which 10 contacts the skin ahead of the blades and the cap 75 which contacts the skin to the rear of the blade.

Relative movement between these elements is sometimes provided for the purpose of enabling the user to obtain more purchase on his beard, i.e. 15 to increase the shaving efficiency and/or to secure 80 a higher degree of conformance to the contours of the shaved area. Relative movement may alternatively be permitted to reduce the risk of injury, for example by allowing the blade edge to 20 move rearwardly away from the guard against a 85 resilient restoring force.

Examples of these two categories are found in British Patent Specifications 1531003 and 1295586 respectively.

25 The present invention is specifically concerned 90 with razors of the type including two blade members having their cutting edges parallel with each other to act in tandem upon the beard, and provide a tandem blade razor in which additional 30 degrees of adjustability between the elements are 95 possible.

The invention includes a tandem blade safety razor head having a leading blade fast with the guard member and a following blade fast with a 35 cap member, and wherein the two said members 100 are interconnected in a manner permitting angular movement of one member and its associated blade relative to the other member about an axis parallel with the cutting edges of the blades. 40 The cap and guard members may be pivotable, 105 independently of each other, about spaced parallel axes parallel with the blade edges. These axes are preferably coincident or closely adjacent the respective blade edges.

45 Both members are preferably spring biased 110 towards an angular position in which the exposure of the associated blade is minimised, so that when greater pressure is exerted on each member, the exposure of the blade carried by the member is 50 increased. 115

Alternatively, the guard and cap members are connected to each other by resiliently flexible bridge portions extending transversely to the blade edges.

55 The invention may be embodied in a disposable 120 razor, i.e. in which the shaving head and handle are integral with each other, or in a cartridge for removable mounting on a razor handle, and is described below in this latter form.

60 Some safety razor heads, or cartridges, in 125

accordance with the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:—

Figure 1 is a cross-section of one form of cartridge;

Figure 2 is an exploded perspective view of the cartridge of Figure 1 drawn to a smaller scale;

Figure 3 is a perspective view of a second form of cartridge;

Figures 4 and 5 are cross-sections, drawn to a larger scale, of the cartridge of Figure 3, with the parts in different relative positions; and

Figures 6 and 7 are a perspective view and a cross-section, corresponding with Figures 3 and 4 of a further form of cartridge.

The cartridge shown in Figures 1 and 2 comprises a generally rectangular frame having opposed side walls 1 and opposed end walls 2. The side walls are formed with channels 3 for coupling the cartridge with a razor handle (not shown) having complementary mounting flanges in well known manner.

Each end wall 2 is formed on its inner face and at its upper edge with a pair of slots 4 which form mounts for the cap and guard members as described below, and with an integral cantilever spring 5 or 6, the spring 5 extending forwardly and the spring 6 rearwardly. Opposite the face end of the spring, each end wall is formed with a rectangular recess 7 or 8 whose purpose is described below.

The frame is conveniently formed as an integral moulding of synthetic plastics material for ease of manufacture.

The guard member 10 is formed as a plastics moulding or as a metal pressing having a guard portion 11 and a rearward extension forming a blade platform 12 to which the leading blade 13 is secured, e.g. by rivetting or welding. A soap slot 14, which may be continuous or interrupted, is formed beneath and forwardly of the blade edge.

At each end, the member 10 is formed with a trunnion 15 which engages in the forward slot 4 at the respective end wall 2 of the frame, so that the guard member is pivotable about an axis coincident with the cutting edge of blade 13. The slots 4 are shaped to permit the trunnions to enter with a snap-fit.

At one end, the guard member is formed with a rearwardly extending finger 16, terminating in an outwardly extending tab 17 which is trapped between the spring 5 and the bottom of recess 7.

The cap member 20 has a forwardly extended portion forming a blade platform 21 to which the following blade 22 is secured. It has trunnions 23 for engagement in the rear slot 4 and at one end a finger 24 and tab 25 engaged between the spring 6 and bottom of recess 8.

In Figure 1, the cap and guard members are shown in their rest position, but they are pivotable against the action of springs 5 and 6, when subjected to pressure during shaving.

The illustrated positions of the skin engaging elements are those in which the blade exposure values are at a minimum, but these values are increased by pivotal movement of the cap and guard members during shaving.

For example, if the cap member 20 is notionally

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fixed in its illustrated position and the guard member 10 pivots anti-clockwise (as viewed in Figure 1) the exposure of the leading blade edge will be increased, but the exposure of the 5 following blade edge (relative to the leading blade 70 edge and cap member) will remain the same.

Conversely, if the guard member 10 is notionally fixed, pivoting of the cap member 20 in the clockwise direction will increase exposure of 10 the following blade without affecting that of the 75 leading blade.

Of course, since both members 10 and 11 are free to pivot, various combinations of blade exposures are possible, together with a high 15 degree of conformance of facial contours. 80

Pivoting of the guard member anti-clockwise reduced the shaving angle of the leading blade,

whilst its blade tangent angle remains constant, and clockwise pivoting of the cap member 20 increases the shaving angle and the blade tangent 85 angle of the trailing blade.

The cartridge illustrated in Figures 3 to 5 comprises a unitary plastics moulding formed with a guard member 31 and a cap member 32 25 extending between end walls 33 which are slotted 90 at 34 to leave integral bridges 36 extending transversely to the length of the cartridge and which are sufficiently thin to permit resilient flexing of the cap member relative to the guard 30 member.

A platform section 37 of inverted L-shape is 95 rigidly connected to the guard member by spaced ribs 38 and carries a leading blade 39 secured as by rivetting to the section 37. The underside of the 35 moulding is locally relieved and shaped to provide a pair of sockets 41, and at a central position with 100 a cam formation 42 to permit the cartridge to be releasably and pivotally mounted on a razor handle of the construction described and 40 illustrated in British Patent Number 1523377.

A second following blade 43 is secured to the 105 underside of the cap member 32 and in the unstressed ("as moulded") condition of the cartridge slopes downwardly and forwardly 45 towards the guard member. In this condition, the cutting edge of the blade 43 has a minimum 110

exposure, preferably a negative exposure, i.e. it is set slightly below a notional plane T drawn through the cutting edge of the leading blade and 50 tangent to the upper surface of the cap member.

In use of the cartridge reaction forces applied to 115 the cap member cause the bridges 36 to flex up to some 6°, so as to tilt the cutting edge of the blade 43 upwardly, thereby increasing its exposure and 55 the shaving angle. This deflection of the cap member and following blade is arranged to take 120 place prior to pivoting of the cartridge on the handle. The deflected position of the parts is shown in Figure 5.

60 In addition to permitting a degree of additional .

conformance to the facial contours and increasing 125 the "purchase" of the following blade in response to pressure applied by the user, the above described construction, by providing a clear space 65 between the blades, allows the razor to be rinsed very efficiently, particularly from the rear of the cartridge where the gap is at its widest.

The cartridge illustrated in Figures 6 and 7 is generally similar in construction and function to that of Figures 3 to 5, except that it is formed from two separate and therefore simpler mouldings which are permanently secured together by snap-fitting.

More specifically, one moulding comprises the platform section 37, modified end walls 51 and a partial guard member 52 of L-shape, the lower limb of which is slotted at intervals. The second moulding comprises the cap member 32, bridges 56 and partial guard member 57 having depending barbs 58 which make snap-fitting engagement in the slots of member 52. These may, for example, be three sets of co-operating barbs and slots, one at the centre of the cartridge and one adjacent each end.

Various modifications will be possible within the scope of the invention. For example, the underside of the cartridge can be modified to fit different razor handles, such as the widely used form having a longitudinal stick engaging in a channel formed on the cartridge, or the cartridge can form the head of a disposable razor.

Claims

1. A tandem blade safety razor head having a leading blade fast with the guard member and a following blade fast with a cap member, and wherein the two said members are interconnected in a manner permitting angular movement of one member and its associated blade relative to the other member about an axis parallel with the cutting edges of the blades.

2. A tandem blade safety razor head having a leading blade fast with a guard member and a following blade fast with a cap member, the said members being pivotable, independently of each other about spaced parallel axes parallel with the blade edges.

3. A razor head according to claim 2, wherein the said axis for each member is coincident with or closely adjacent the cutting edge of the blade carried by that member.

4. A razor head according to claim 2 or 3, wherein the said members are each spring biased towards an angular position in which the exposure of the associated blade is minimised.

5. A razor head according to claim 2, 3 or 4, wherein the said members are mounted in a generally rectangular frame by pivotal mounting means at the ends of the said members.

6. A razor head according to claim 1, wherein the said guard and cap members are connected to each other by resiliently flexible bridge portions extending transversely to the blade edges.

7. A razor head according to claim 6, wherein the guard member is fast with a blade platform on which the leading blade is secured and the blades define between them a rinsing passage extending the full length of the blades.

8. A razor head according to claim 6 or 7, wherein the guard member is fast with a coupling

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portion by which the razor head can be detachably coupled to a co-operating razor handle.

9. A razor head according to claim 6,7 or 8, wherein the guard member and cap member form

5 parts of a unitary moulding in which the said members are integrally connected at their ends by the said bridge portions.

10. A razor head according to claim 6 or 7, wherein the two blades are fastened to respective,

10 separate mouldings which are securely connected together to form the razor head.

11. A razor head substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings.

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12. A razor head substantially as herein described with reference to Figures 3,4 and 5 or Figures 6 and 7 of the accompanying drawings.

Printed for

Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.